Exp 1 Quantitative determination of glucose in serum
- Slides: 8
Exp #1 Quantitative determination of glucose in serum or plasma by GOD-POD method
Glucose is a major carbohydrate present in the peripheral blood. The oxidation of glucose is the major source of cellular energy in the body. Glucose determinations help to diagnose and treat the diabetes mellitus(D. M). The blood glucose level is normally maintained within a narrow range under various conditions by hormones , such as insulin, glucagon, or epinephrine. Patients with diabetes demonstrate an inability to produce insulin. Clinical diagnosis should not be made on a single test result.
Clinical significance: Elevated glucose associated with: pancreatitis, pituitary or thyroid dysfunction, renal failure and liver disease Low glucose associated with: insulinoma, hypopituitarism , neoplasms, or insulin hypoglycemia
Principle: Glucose+O 2+H 2 O GOD Gluconic acid +H 2 O 2+4 aminoantipyrine +PHBA dye(red color) +4 H 2 O POD quinoneimine The quinoneimine dye has an absorption maximum at 505 nm. The amount of color produced is directly proportional to the glucose content of the sample
*GOD=glucose oxidase *PHBS=p-hydroxybenzoic acid *POD=peroxidase *Specimen: Serum or plasma or CSF Free of hemolysis or clot(glycolysis) Stability: stable at 2 -8 ºC for one day.
Procedure: 1. Assays conditions: Wavelength…………. . 505 nm Cuvette………………. 1 cm light path Temperature…………. 37 ºc 2. Adjust the instrument to zero with distilled water
3. Pipette into a cuvette Standard Test(Sample) WR - µl 1000 Standard -µl 10 -- Test sample -- 10 4. Mix and incubate for 10 min at 37ºc 5. Read the absorbance (A) at 505 nm. * The color is stable for at least 60 min
Calculation (A)Sample x 100(std conc)= mg/dl (A)standard Normal Range: Serum: 75 -115 mg/dl
